Patent literature 1: Japanese Patent No. 3341664 B2
For example, patent literature 1 discloses image analysis captured by an onboard camera to detect a parking compartment line. Patent literature 1 detects a parking compartment line based on a change of a brightness value in an image captured by the onboard camera. When one pair of parking compartment lines is detected, a space between the parking compartment lines is recognized as a parking compartment, which is a parking space.
The inventors of the present application have found the following.
An image captured by an onboard camera may include a portion where a brightness value changes, in addition to a boundary of parking compartment lines. A portion other than the parking compartment lines may be erroneously recognized as a parking compartment line. When no parking compartment line is present, a parking space may not be determined.